Ceiling panel hoist



April 15, 1958 R. COTTAR Q 2,830,854

CEILING PANEL HOIST Filed oct. 18. 1954 2 Sheets-Sheet 1 5 INVE'NTOR '5 6 58 1 5 206 12 Coffer BY Mama- April 15, 1958 R. COTTAR 2,330,854

' CEILINGYPANEL I-IOIST Filed Oct. 18. 1954 2 Sheets-Sheet 2 INVENTOR WM div WM) United States Patent CEILING PANEL HOIST Robert Cottar, Red Bluff, Calif.

Application October 18, 1954, Serial No. 462,895

1 Claim. (Cl. 304-29) to provide a hoist, for the described purposes, which in cludesin connection between a ceiling panel supporting platform and a base framel1and, Windlass actuated pantograph or lazy-tongs type lever arm assemblies operative as a unit to raise or lower said platform, while maintaining the same horizontal atall times.

An additional object of this invention is to provide the hoist with a novel starting leverage mechanism which cooperates with the Windless to greatly increase the mechanical advantage; i. e., the lifting force applied to said lever arm assemblies by the Windlass during the initial extension of such assemblies from a full lowered or contracted position, whereby to materially reduce the manual effort required at the outset of each panel lifting operation.

A separate object of the invention is to provide a ceiling panel hoist which, when in lowered or contracted position, is quite compact and adapted to be disposed on end for storage or for passage through a door when being moved from room to room in a building; there being caster wheels positioned to support the hoist on end for rolling on the floor from place to place.

It is also an object of the invention to provide a ceiling panel hoist which is designed for ease and economy of manufacture and convenience of use.

Still another object of the invention is to provide a practical, reliable, and durable ceiling panel hoist, and one which will be exceedingly eifective for the purpose for which it is designed.

These objects are accomplished by means of such structure and relative arrangement of parts as will fully appear by a perusal of the following specification and claim.

In the drawings:

Fig. l is a side elevation of the ceiling panel hoist in lowered or contracted position.

Fig. 2 is a similar view, but shows the hoist partially raised or extended.

Fig. 3 is an enlarged fragmentary side elevation illustrating particularly the starting leverage mechanism in play.

Fig. 4 is an enlarged fragmentary transverse section on line 4-4 of Fig. 2.

Fig. 5 is an end elevation of the hoist in lowered or contracted position, as in Fig. 1; the view looking at the end of the device on which the Windlass is mounted, and the releasable catches being shown in engaged position.

Fig. 6 is an enlarged fragmentary transverse section on line 6-6 of Fig. 2.

Figure 7 is a side elevation of the ceiling panel hoist contracted and upended to rest on its caster wheels.

Referring now more particularly to the drawings, and

2,83fi,854 Patented Apr. 15, 1958 'ice to the characters of reference marked thereon, the ceiling panel hoist comprises a base frame and-thereabove in symmetrical relationa ceiling panel supporting platform, indicated generally at ft and 2, respectively; such base frame 1 and ceiling panel supporting platform 2 both being horizontal, elongated, and of open construction.

The base frame 1 includes side bars 3 and transverse end bars 4; said base frame being normally supported at opposite ends from the floor by transverse feet 5. The ceiling panel supporting platform 2 includes longitudinal side bars 6 and transverse end bars '7.

The base frame it and ceiling panel supporting platform 2 are connected at each side by a vertically extensible pantograph or lazy-tongs type lever arm assembly, indicated generally at 8; the assemblies being worked in unison, as will hereinafter appear, to move the ceiling panel supporting platform 2 from a full lowered or contracted position adjacent the floor to a raised or extended position with a ceiling panel Pcarried by said platformin engagement with the ceiling joists for convenient securing to the latter.

Each lever arm assembly 8 comprises a pair of intersecting lower lever arms 9 and 10 pivoted together at the point of intersection, as at 11, and a pair of intersecting upper lever arms 12 and 13 pivoted together at the point of intersection, as at 14.

The adjacent ends of the lever arms 9 and 13 are pivoted together, as at 15, while the adjacent ends of the lever arms fill and 12 are pivoted together, as at 16.

The lower end of each lever arm 9 is pivoted, as at 17, to an ear l8 fixed on the corresponding longitudinal side bar 3 adjacent one end thereof. The lower end of each lever arm 14) is fitted with a roller 19 which runs in a longitudinal guide channel 20 formed on the adjacent portion of the corresponding longitudinal side bar 3.

The rollers 19 on the lower ends of the lever arms 10 are connected by a cross shaft 21 which also carries-adjacent each roller l9-a fixed pulley 22; the purpose of the pulleys 22 being hereinafter described.

The upper end of each lever arm 13 is pivoted, as at 23, to an ear 24 fixed on the corresponding side bar 6 near the adjacent end thereof.

At its upper end each lever arm 12 is connected to a roller 25 by means which includes a cross shaft 26 extending between both of the lever arms 12. Each roller 25 is engaged between the bottom of the corresponding longitudinal side bar 6, and a longitudinal supporting rod 27 secured to, but spaced below, said side bar; lateral displacement of each roller 25 from between the related side bar 6 and rod 27 being prevented by a Ushaped guide 28 which straddles such roller and said side bar.

At the ends adjacent the ears t8 the base frame 1 is fitted with a rigid upstanding end frame, indicated generally at 29; said end frame including side posts 30 connected by a transverse top bar Bl. The end frame 29 is stabilized by diagonal bracing 32.

A transverse Windlass shaft 33 is journaled on the end frame 29 adjacent the top thereof, and such shaft 33 is fitted with a pair of Windlass drums 34 spaced apart substantially the same distance as the spacing of the pulleys 22 on the cross shaft 21.

At one end thereof the Windlass shaft 33 is fitted, laterally of the end frame 29, with a hand crank 35, and a releasable pawl and ratchet unit 36 is connected between the same end of the Windlass shaft 33 and the end frame 29.

Cables 37 are fixed to the Windlass drums 34, thence extend to and turn over corresponding pulleys 22, and then retum within the base frame 1 in the direction of the end frame 29; being secured to a cross member 38 in base frame 1 by anchor bolts 39.

Upon actuation of the hand crank in a direction to wind the cables 37 onto the Windlass drums 34, the pulleys 22, together with the cross shaft 21 and the lower ends of the lever arms 16 are drawn or moved in the direction of the end frame 29, with the result that the pantograph or lazy-tongs lever arm assemblies 8 are extended in unison, whereby to raise the ceiling panel supporting platform 2 from a lowered position to a raised position, as aforesaid. When this occurs the rollers 19 travel in the longitudinal guide channels 20,- while the rollers 25 travel lengthwise between the side bars 6 and supporting rods 27.

In order to increase the mechanical advantage between the Windlass arrangement and the lever arm assemblies 8 at the outset and during the initial extension of said assemblies, the following novel starting leverage mechanism is employed:

The pivots 16 for the adjacent ends of the lever arms 10 and 12 are included with a cross shaft on which is fixed a pair of transversely spaced, dependent thrust arms 41; the. spacing of such thrust arms 41 being substantially the same as the spacing of the cables 37.

A control link 42 is pivoted at one end, as at 43, to each thrust arm 41 intermediate the ends of the latter and thence extends inwardly to pivotal connection, as at 44, with the related lever arm 9 between the pivots 11 and 17, being closer to the former.

At the lower end thereof each thrust arm 41 is fitted with, a roller 45 carried on a cross shaft 45:: which extends between said ends.

When the hoist is in its lowered position, with the lever arm assemblies 8 contracted, the rollers 45 engage the corresponding cables 33 inwardly of the Windlass shaft 33 and deflect such cables downwardly so that they extend substantially horizontally between said rollers 45 and the pulleys 22. Consequently, at the start and during the initial portion of each hoist raising or extending operation, there is a great gain in mechanical advantage as the cables 31 wind onto the Windlass drums 34. v

In addition to the cable action on the pulleys 22 being at a lesser acute angle, there is an upward thrust imparted by the arms 41 to the lever arm assemblies 8 at the pivot 16; both substantially aiding in starting and accomplishing the initial extension of the lever arm assemblies 8.

After such extension is partially accomplished, and at which time the mechanical advantage on a direct or straight-line pull between the Windlass drums 34 and pulleys 22 is satisfactory, the rollers 45 escape the cables 37, and extension of the hoist continues without undue effort on the part of the operator actuating the hand crank 35 being required.

When the ceiling panel supporting platform 2 is in its lowered position, such platform abuts the transverse top bar 31, and is adapted to be releasably maintained in such position by catches 46, which catches are normally swung to an inoperative position, as shown in dotted lines in Fig. 5.

When it is desired to store the hoist, or to move it from place to place, such hoist is contracted, the catches 46 are engaged, and the hoist is then turned on end with the end frame 29 lowermost, as shown in Fig. 7. The frame 29 is fitted, on the outside and at the corners,

4 with caster wheels 47 which support the hoist in its up-ended position for ease of movementon the. floor; such hoist when contracted and up-ended being capable of movement through a door.

From the foregoing description it will be readily seen that there has been produced such a device as will substantially fulfill the objects of the invention, as set forth herein.

While this specification sets forth in detail the present and preferred construction of the device, still in practice such deviations from such detail may be resorted to as do not form a departure from the spirit of the invention, as defined by the appended claim.

Having thus described the invention, the following is F claimed as new and useful, and upon which Letters Patent are desired:

A ceiling panel hoist comprising a base frame, a ceiling panel supporting platform spaced above the base frame, an initially contracted vertically extensible lever arm assembly connecting the. base frame and platform, said lever arm assembly including lower lever arms intersecting and pivoted together intermediate their ends, means pivoting the. lower end of one of said arms on the base frame, means on the base frame guiding the lower end of the other one of said arms for movement toward and from the lower end of said one arm, a rigid frame upstanding from the base frame clear of said lever arm assembly. and outwardly of the lower end of said one arm, a Windlass including a drum journaled in the upstanding frame. above the base frame, a cable on the drum extending thence to. the lower end of said other member at a normally downward incline and adapted to pull the same toward the lower end of said one arm, a thrust arm pivoted in connection with and depending from the upper end portion of said other arm, a pulley depending from the thrust arm in position to engage and deflect the cable downwardly intermediate its ends when said assembly is contracted and during initial extension thereof whereby the effective line of pull is then. from a lowered point, and a control link pivotally connected between the thrust arm and said one lever arm in a manner to maintain the thrust arm in a dependent positionduring contraction or extension of said lever arm assembly and so that the pulley will move in a vertical plane whereby such plane may be adjacent that of windlass without interference therefrom during such contracting and extending movement of the lever arm assembly.

References Cited in thefile of this patent UNITED STATES PATENTS 285,273 Josel Sept. 18, 1883 636,445 McCabe et al. Nov. 7, 1899 1,031,818 Putman July 9, 1912 1,078,759 Wichertjes Nov. 18, 1913 1,627,559 Haul May 10, 1927 1,817,418 Munns Aug. 4, 1931 2,370,887 Soskin Mar. 6, 1945 2,468,230 Pollard Apr. 26, 1949 2,512,534 Shaw June 20, 1950 FOREIGN PATENTS 8,603 Great Britain Apr. 18, 1907 130,215 Australia Nov. 23, 1948 204,356 Switzerland Apr. 30, 1939 513,255 Belgium July 31, 1952 

